The advantages of having a passenger or cargo vehicle with a flat load floor are well known. Heavy-duty trucks usually have longitudinally mounted front engines and rear drives. A flat load floor is obtained with such vehicles by raising the load floor to a sufficient height to clear all obstructions beneath the load floor. The load floor height can be approximately about four feet. Heavy-duty busses obtain a somewhat lower flat floor area in the forward part of the bus by providing a transversely mounted rear engine that drives rear wheels. The complexities of such a drive make it expensive. As to smaller vehicles, such as medium duty trucks and busses, it is desirable to have a low load floor, as well as a flat load floor. A low step height into the vehicle makes the vehicle much more accessible for loading both passengers and cargo. However, in smaller vehicles, including medium duty busses and trucks, a rear engine/rear drive power package is not a commercially viable option.
It is well known that one can obtain a low flat load floor in a vehicle by disposing the vehicle engine and power train wholly in the front of the vehicle. Such vehicles are already commercially available. Such a vehicle can provide a low step height to the load floor that makes the vehicle much more accessible for loading both passengers and cargo. However, the utility of such vehicles is limited because the driving wheels are not located under the part of the vehicle carrying the load. Improved weight balance and load-carrying capacity is achieved if the engine is in the front of the vehicle and the driving wheels are in the back of the vehicle, under the load.
Because of low load floor front drive trucks and busses have practical limitations, there is still interest in finding an economical rear drive truck and bus that has a low load floor. In addition, disposing the vehicle engine in the front of the vehicle leaves the back of the vehicle more available for passengers and/or cargo. Further, it should be understood that extensive worldwide manufacture and sales of front-engine/rear drive trucks and buses has provided a vast engineering and use experience with front engine/rear drive power trains. This vast experience has provided lowest cost and highest durability for such power trains. For these and other reasons, there is continued manufacture and use of front-engine/rear drive trucks and buses, even though their load floors are relatively high. Because of this extensive production and use experience, there continues to be interest in utilizing front engine/rear drive power trains for low profile and/or low load floor vehicles. However, until my design innovation, no commercially practical design for such a vehicle has been discovered.
It would be of considerable commercial advantage if a low and flat load floor vehicle could be made using mostly traditional front engine/rear drive components. If so, the traditional components would be useful in the manufacture of both the traditional and the low profile vehicles. It would be of even greater advantage if the low load floor vehicle and the traditional vehicle were generally the same forward of the load floor. This will tend to reduce development costs of the low profile vehicle, and make it manufacturable at lower cost and higher durability. I have discovered how to attain this goal. My discovery is particularly of interest to medium duty trucks and busses, where rear drive is quite important.